Samsung Qi Wireless Charger, how can I fix it?

I've got a Galaxy S6, the official charger that came with the S6 and the official wireless charger. I get a blinking green light when I plug the wireless charger in which indicates the wall charger is under 2A, but the charger is (it's the official charger which Samsung have confirmed is sufficient).

It should be, but I haven't seen anything that says otherwise... You might have to place it differently when you have the case on then. Try placing it lower or higher or sideways to see which one works best.

Without the case if I place it with the top of the phone too low on the charger, it will blink.